Machine compartment arrangement for a refrigerating device

ABSTRACT

For a domestic refrigerator or freezer, a machine compartment arrangement to improve cooling of the compressor and condenser therein by providing double, serially-arranged fans, the upstream one being arranged to draw air through the condenser, and the downstream one being arranged to direct air directly against the compressor. The arrangement is also intended to maintain a cooling air flow against the compressor as dirt builds up on the upstream face of the condenser by providing a bypass around the condenser in the plenum in which the condenser is located. Additionally, the inlet air duct to the machine compartment has its inlet spaced above the floor, and a clean-out door giving access to the upstream face of the condenser is provided in the back wall of the machine compartment.

United stateS Patent 91 1 1 3,736,768 Harbour et al. 51 June 5, 1973 [54] MACHINE COMPARTMENT ARRANGEMENT FOR A Primary Examiner-Meyer Perlin REFRIGERATING DEVICE A tt0rneyF. H. Henson and E. C. Arenz [75] Inventors: Philip F. Harbour; Charles A. Wilcox, both of Columbus, Ohio [57] ABSTRACT [73] Assignee: Westinghouse Electric Corporation, For a domesnc refrgeramf or freezer a machme partment arrangement to improve cooling of the com- Pittsburgh, Pa.

pressor and condenser therein by providing double, [22] Filed: June 29, 1971 serially-arranged fans, the upstream one being ar- [21] p No: 157,897 ranged to draw air through the condenser and the downstream one being arranged to direct air directly against the compressor. The arrangement is also in- U-S. Cl. tended to maintain a cooling air flow against the com- Il'lt. pressor as dirt up on the upstream face the Fleld of Search condenser providing a bypass around the Con. 62/289, 303, 456 denser in the plenum in which the condenser is located. Additionally, the inlet air duct to the machine [56] References C'ted compartment has its inlet spaced above the floor, and UNITED STATES PATENTS a clean-out door givingaccess to the upstream face of i the condenser is provided in the back wall of the 3,162,023 12/1964 Smith.... ..62/455 machine compartment. 3,079,770 3/1963 Brown... .....62/455 3,230,734 1/1966 Koch ..62/455 5 Claims, 5 Drawing Figures 34 K 26 j i l6 42 36 I 46 o u 2l m 32 2 12 3o PATENTED JUH 5 I975 SHEU 1 OF 2 PATENTEUJUH 5|975 3.736.768

sum 2 OF 2 FIG. 5

MACHINE COMPARTMENT ARRANGEMENT FOR A REFRIGERATING DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains generally to the art of machine compartment arrangements for a refrigerating device in which forced air cooling of the refrigerant condenser and compressor occurs.

2. Description of the Prior Art Of the prior art of which applicants are aware, one arrangement having structural similarities is the refrigerating device of applicants assignee. In this prior art arrangement, the machine compartment is arranged with the cooling fan, condenser, and compressor in series along the back portions of the machine compartment. The fan is on the upstream side of the condenser and draws air from floor level at the front of the refrigerator and discharges it against the upstream face of the condenser. After the air passes through the condenser, it flows through the area in which the compressor is located and then forwardly across the upper surface of the drip pan and, for the most part, back out the front of the machine compartment. With this arrangement the volume of air flow over the compressor is sometimes inadequate, even though the condenser is clean, due to the restriction to air flow imposed by the condenser itself and to the diffusion of the air stream by the condenser. Further, the airborne grease, lint and dust particles picked up in the air drawn into the machine compartment eventually blocks the upstream face of the condenser to a greater or lesser degree and further reduces the air flow which reaches the compressor. An air filter on the upstream side of the condenser is not considered to provide a solution since it also would tend to become clogged and restrict the air flow. Further, in its concealed position few users of the refrigerator would be likely to periodically check and clean the filter. While in such an arrangement it is possible to clean the fan and condenser, this is difficult to accomplish because the rear cover of the machine compartment must be removed, and the dirty inlet face of the condenser is accessible only through a narrow slot making cleaning of the entire surface extremely difficult.

With this prior art arrangement, the clogging of the condenser results in both reduced air flow over the compressor, and an excessive rise in condensing temperatures. This condition may, in turn, result in sufficiently elevated compressor temperatures that it fails.

It is also acknowledged that the prior art includes arrangements in which a single fan is located between a condenser and compressor.

Accordingly, our invention is directed to an improved arrangement to substantially reduce the chance of inadequate cooling of the condenser and compressor.

SUMMARY OF THE INVENTION In accordance with the invention, the electric motor has a double shaft extension, is provided with an upstream fan on the shaft at the end of the motor facing the condenser, and a downstream fan on the shaft at the end of the motor facing the compressor. .The upstream fan functions as a draw-through fan pulling air through the condenser, and the downstream fan functions as a blow-through fan which discharges air directly against the compressor. Additionally, the con denser is located in a plenum which has a downstream wall thereof including a fan ring opening in which the upstream fan is located, and the cross-sectional area of the plenum is sufficiently greater than the crosssectional area of the condenser to provide a bypass for air flow around the condenser in accordance with the resistance to air flow imposed by the condenser.

The compartment is also arranged so that the air inlet duct through which air passes to the condenser has its inlet openings spaced above the floor to reduce the amount of dirt pickup from the floor. Also, a clean-out door is provided in the vertical rear wall of the machine compartment to permit access to the upstream face of the condenser.

DRAWING DESCRIPTION FIG. 1 is a generally schematic view in the nature of a top plan view of the machine compartment to illustrate the general locational relationship of the parts, and the air flow through the machine compartment;

FIG. 2 is a perspective view looking in the rear of the machine compartment;

FIG. 3 is a fragmentary perspective view of the righthand portion of the machine compartment as viewed from the bottom of the refrigerator and especially illustrating the manner in which the inlet air duct is provided;

FIG. 4 is a partly-broken, fragmentary, elevational view of the righthand lower portion of the refrigerator; and

FIG. 5 is a fragmentary perspective view of the rear and lefthand side of the lower portion of the refrigerator showing the rear cover with the access door in place at the rear of the machine compartment.

DESCRIPTION OF THE PREFERRED EMBODIMENT As seen in FIG. 1, the machine compartment 10 of the refrigerator is formed by a casing which includes opposite side walls 12 and 14 constituting downward extensions of the sidewalls of the refrigerator shell, and which are flanged inwardly at the bottom to form the bottom side rails 16 and 18. The lower portion of the front of the machine compartment is open and has an openwork grill 20 covering the opening. Substantially all of the height of the rear of the machine of the compartment is open to permit the installation and access to the unit pan 22 upon which is mounted the compressor 24, condenser 26, and fan motor 28. In use, the rear opening of the machine compartment is closed by a cover 30 (also see FIG. 5) which includes a cleanout door 32 which will be referred to later herein.

The bottom of the machine compartment is open, and the top is covered by a wall and thermal insulation (neither shown) which separates the machine compartment from the lower end of the refrigerated space.

The condenser 26 as seen in FIGS. 1 and 2 is of generally conventional structure and of two-pass character. A continuous tube is bent into a flattened loop of alternate upstream and downstream tubes at successively higher positions. Of course, the tubes in both passes are spaced apart from each other so that the condenser as a whole is of generally open-work structure to permit air flow therethrough. The condenser tube passes are supported at their return ends by the walls 34 and 36 which include slots in their inwardly directed, V-shaped portions to space the tubes from each other in a vertical direction. These walls 34 and 36, along with a downstream wall 38 (FIG. 2) and the overlying top wall of the machine compartment form what may be considered a plenum for the condenser. An opening 40 in the downstream wall accommodates the upstream fan 42.

The motor 28 is carried from the downstream wall 38 by a spider support 44. As noted before, the motor has a projecting shaft at each of its opposite ends. The upstream draw-through fan 42 is mounted on the shaft at the upstream end of the motor, and a downstream fan 46 is mounted on the shaft of the opposite end of the motor.

The air flow path through the machine compartment is as follows. Air is drawn from in front of the refrigerator and from above the floor into the inlet duct 48, which will be described later herein, to the space in the rear, righthand comer of the machine compartment upstream of the condenser 26, then through the condenser by the draw-through fan 42. This air is then directed against the compressor 24 by the downstream fan 46, which squarely faces the compressor. The air then passes back toward the front of the machine compartment over the upper surface of the drain pan 50 and out through the outlet opening of the toe grille 20.

To insure that the air flow through the condenser plenum will not be blocked even though the condenser tends to clog, a bypass space in the plenum is provided above the condenser. This is obtained by making the height of the plenum greater than the height of the condenser. Accordingly, as seen in FIG. 2 the downstream wall 38 extends upwardly well above the top edge of the condenser. Since the condenser is of two pass construction and is open between the two tubes at the top of the front and rear passes, even if the upstream face of the condenser becomes clogged, air can flow up over the top edge of the upstream tubes and then down and past the downstream tubes to accomplish some cooling of the downstream tubes of the condenser. Furthermore, even if under extremely dirty conditions both the upstream and downstream tube passes of the condenser become relatively restricted to the passage of air flow therethrough, the air can bypass both faces of the condenser and still be drawn through the fan plenum by the upstream fan 42 and discharged against the compressor 24 by the downstream fan 46. In this connection it is noted that while both condenser cooling and compressor cooling contribute to a satisfactorily operating system, excessive heating of the compressor will more likely result in damage to the system than overheating of the condenser alone.

Referring now to FIGS. 3 and 4, the inlet duct 48 may be formed up out of fiber board into a shape cooperating with the other refrigerator wall structure to form the duct. As such, it includes a bottom wall also designated 48 which has its forward edge 52 aligned generally in the plane of the front face of the machine compartment, but spaced above the floor as shown to prevent the inlet air from easily picking up contaminating particles from the floor. The lefthand of the side wall 54 of the duct extends rearwardly to a location immediately in front of the condenser plenum and includes a right angle flange wall 56 thereon to block the slotted portion of the plenum wall 34 to insure that the air will pass therearound to the space upstream of the condenser.

The opening across the front of the machine compartment, which is best seen in FIGS. 3 and 4, is covered by the toe plate 20 which has the general form of an open-work grille divided by a horizontal solid portion and which is V-shaped in transverse cross section to receive the forward edge 52 of the bottom wall of the inlet duct. It is preferred that at least the air intake portion of the toe grille 20 consist of relatively small openings which effectively act as a sieve type air filter and so that fibrous or linty particles will accumulate thereon and serve to indicate to the unit user when it is advisable to both clean this material off the toe grille, and to also clean off the upstream face of the condenser. In other words, the accumulation of dirty mate rial both on the inlet to the toe grille and on the upstream face of the condenser will normally be related to each other.

Referring now to FIG. 5, the cover 30, which also may be of fiber board, closes the opening at the rear of the machine compartment. A cleanout door 32 is provided in this fiber board cover to give access to the upstream face of the condenser. This door is designed to be fastened closed and to be opened without the use of tools to make it easier for the user to gain access for cleaning. Cleaning may be accomplished by various means such as a vacuum cleaner wand attachment, a brush, a rag, or any combination of these. It is also not considered important that the cleanout door 32 seal tightly, since leakage of the air therethrough is to the proper place upstream of the condenser.

With the arrangement shown and described, the condenser can accept a considerably higher degree of clogging before a severe loss in condenser cooling effect occurs, since even if the upstream face of the condenser is clogged, the downstream face will likely be open to at least a limited degree. If the condenser should be fully clogged, the bypass arrangement in the plenum permits air to be drawn through the plenum and forcibly discharged by the serially arranged fans against the compressor. It will be appreciated that with the serial fan arrangement an increased volume of air flow is provided as compared to a single fan of the same size. Also, by directing air forcibly against the compressor withthe downstream fan 46, an increased coefficient of heat transfer is provided. The location of the inlet air opening results in lower dust concentration in the inlet air, and to the extent that dust is draw in, it effectively is signaled by a proportional buildup on the toe grille. Finally, for cleaning purposes the toe grille is conveniently accessible, and the condenser face is also relatively accessible.

What is claimed is:

1. A machine compartment arrangement for a refrigerating device, comprising:

means defining a casing for said machine compartment at the bottom end of said refrigerating device; a refrigerant compressor in said casing; a refrigerant condenser in said casing; an electric motor having a double shaft extension located between said condenser and compressor;

an upstream fan on the shaft at the end of said motor facing said condenser, and a downstream fan on the shaft at the end of said motor facing said compressor;

an upstream fan on the shaft at the end of said motor facing said condenser, and a downstream fan on the shaft at the end of said motor facing said compressor;

means defining a path for said air flow in sequence through said condenser, said upstream fan, said downstream fan, and across said compressor;

said path defining means includes a plenum in which said condenser is located, the downstream wall of said plenum including means defining a fan ring opening in which said upstream fan is located;

said condenser has a cross sectional face area less than the cross sectional area of said plenum transverse to the normal path of said air flow to provide a bypass through which air flows in accordance with the resistance to air flow imposed by said condenser;

said condenser comprises both an upstream and a downstream portion whereby blockage of said upstream portion does not preclude air flow to cool said downstream portion.

2. An arrangement according to claim 1 wherein:

said upstream and said downstream fan comprise propeller fans; and

said downstream fan substantially squarely faces said compressor to discharge air directly thereagainst.

3. An arrangement according to claim 1 wherein:

said machine compartment is generally rectangular in outline as viewed in plan, said condenser is located in one rear corner portion and said compressor is located in the other rear corner portion, and said path defining means includes an inlet at the front of the forward corner portion forwardly of said rear corner portion in which said condenser is located.

4. An arrangement according to claim 3 wherein:

said path defining means includes an air inlet duct in said forward corner portion, the bottom wall of said duct having a forward edge spaced above the floor and generally in the plane of the front face of said machine compartment so that air is drawn into said inlet duct from forwardly of the refrigerating device, and from above the floor to reduce pickup of dust.

5. An arrangement according to claim 3 wherein:

a vertical rear wall for said machine compartment,

including a clean-out door therein located to permit access to the upstream face of said condenser when said door is open. 

1. A machine compartment arrangement for a refrigerating device, comprising: means defining a casing for said machine compartment at the bottom end of said refrigerating device; a refrigerant compressor in said casing; a refrigerant condenser in said casing; an electric motor having a double shaft extension located between said condenser and compressor; an upstream fan on the shaft at the end of said motor facing said condenser, and a downstream fan on the shaft at the end of said motor facing said compressor; an upstream fan on the shaft at the end of said motor facing said condenser, and a downstream fan on the shaft at the end of said motor facing said compressor; means defining a path for said air flow in sequence through said condenser, said upstream fan, said downstream fan, and across said compressor; said path defining means includes a plenum in which said condenser is located, the downstream wall of said plenum including means defining a fan ring opening in which said upstream fan is located; said condenser has a cross sectional face area less than the cross sectional area of said plenum transverse to the normal path of said air flow to provide a bypass through which air flows in accordance with the resistance to air flow imposed by said condenser; said condenser comprises both an upstream and a downstream portion whereby blockage of said upstream portion does not preclude air flow to cool said downstream portion.
 2. An arrangement according to claim 1 wherein: said upstream and said downstream fan comprise propeller fans; and said downstream fan substantially squarely faces said compressor to discharge air directly thereagainst.
 3. An arrangement according to claim 1 wherein: said machine compartment is generally rectangular in outline as viewed in plan, said condenser is located in one rear corner portion and said compressor is located in the other rear corner portion, and said path defining means includes an inlet at the front of the forward corner portion forwardly of said rEar corner portion in which said condenser is located.
 4. An arrangement according to claim 3 wherein: said path defining means includes an air inlet duct in said forward corner portion, the bottom wall of said duct having a forward edge spaced above the floor and generally in the plane of the front face of said machine compartment so that air is drawn into said inlet duct from forwardly of the refrigerating device, and from above the floor to reduce pickup of dust.
 5. An arrangement according to claim 3 wherein: a vertical rear wall for said machine compartment, including a clean-out door therein located to permit access to the upstream face of said condenser when said door is open. 